William ate 1 slice of pizza. Umaima ate 4 slices. If William ate $\dfrac{1}{7}$ of the pizza, what fraction of the pizza is remaining?
Answer: If 1 slice represents $\dfrac{1}{7}$ of the pizza, there must have been a total of 7 slices. $\text{fraction of pizza remaining} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 5 slices, which leaves 2 out of 7 slices remaining. There is $\dfrac{2}{7}$ of the pizza remaining.